in this study, the effect of the levels of hydrogen addition to methane-air premixed flame in a micro-stepped reactor has been studied numerically. in addition, the effects of mixture velocity and walls’ thermal conductivity (kw) on the flame’s location, temperature, and species distribution in a micro reactor were calculated using a 2d numerical laminar steady code. the results showed that an ...

In reacting flow problems involving large numbers of chemical species and reactions, reduced chemistry modeling is used to approximately describe, with fewer unknowns, the slow chemical evolutions after the rapid but brief initial transients have decayed. Diffusion transport terms, if present, are modified by the reduced chemistry approximations. This article reiterates that the use of unmodifi...

ball mills are common grinding equipment in mineral processing industries. ball wear results from three mechanisms namely impact, abrasion and corrosion. of these, the corrosion mechanism is the least investigated, due to its chemical-electrochemical nature. therefore, the aims of this research were to investigate the grinding chemistry influence (slurry ph, solid percentage, water chemistry an...

This is a tutorial on reduced chemistry modeling and sensitivity analysis using computational singular perturbation, or CSP. After briefly presenting the underlying mathematics, the exposition focuses on how to use CSP data to neglect the non-participating elementary reactions in the reaction database, to trim the number of relevant reactants, and how to identify the so-called “CSP radicals” an...

We propose a density functional perturbative scheme to approximate the energy of a high-level DFT calculation at a significantly reduced cost. Our approach involves performing a primary SCF calculation using a crude functional, basis set and quadrature grid, followed by a single step using a more sophisticated secondary functional, basis and grid. Unlike the earlier dual-level DFT approach of N...

Ball mills are common grinding equipment in mineral processing industries. Ball wear results from three mechanisms namely impact, abrasion and corrosion. Of these, the corrosion mechanism is the least investigated, due to its chemical-electrochemical nature. Therefore, the aims of this research were to investigate the grinding chemistry influence (slurry pH, solid percentage, water chemistry an...